Regional shifts in paleohurricane activity over the last 1500 years derived from blue hole sediments offshore of Middle Caicos Island
Regional shifts in paleohurricane activity over the last 1500 years derived from blue hole sediments offshore of Middle Caicos Island
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DOI：
10.1016/j.quascirev.2021.107126
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发表时间：
2021-09
影响因子：
4
通讯作者：
E. Wallace;J. Donnelly;P. J. Hengstum;T. S. Winkler;Charmille Dizon;Alexandra LaBella;I. López;N. D’Entremont;R. Sullivan;J. Woodruff;A. Hawkes;C. Maio
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作者：
E. Wallace;J. Donnelly;P. J. Hengstum;T. S. Winkler;Charmille Dizon;Alexandra LaBella;I. López;N. D’Entremont;R. Sullivan;J. Woodruff;A. Hawkes;C. Maio
沿海社区容易受到海平面上升和飓风引发的洪水的影响。我们评估沿海地区水浸风险的能力受到短期观测记录和对不同强度、大小和方向的飓风期间风暴潮产生的有限知识的限制。在这里，我们展示了从特克斯和凯科斯群岛中凯科斯群岛附近的一个蓝洞收集的沉积岩芯的横断面。在样带岩芯中发现的风暴沉积记录了过去1500年来向中凯科斯以南移动的飓风的经过，包括2017年的飓风伊尔玛。这一记录表明，该岛经历了史无前例的数十年风暴袭击。我们将这一新的重建添加到巴哈马群岛过去千年以来几乎每年解析的古飓风记录汇编中。这一汇编表明，巴哈马群岛的风暴活动从公元650到800、公元930到公元1040和公元1400到公元1800都有所增加。结合新英格兰和佛罗里达州墨西哥湾沿岸已公布的古飓风记录汇编，我们观察到过去1000年来所有三个空间不同地区的飓风活动高峰期，以及新英格兰和巴哈马群岛活跃而佛罗里达州墨西哥湾沿岸不活跃的时期。我们认为，垂直风切变模式的区域尺度变化和风暴路径的移动都可以解释我们观察到的北大西洋不同区域之间的差异。这项研究提供了过去1500年来飓风频率的变化情况，特别是在特克斯和凯科斯群岛以及巴哈马群岛沿线地区。
Coastal communities are vulnerable to sea-level rise and hurricane-induced flooding. Our ability to assess flooding risk at coastal locations is restricted by the short observational record and limited knowledge on storm surge generation during hurricanes of different strength, size and orientation. Here, we present a transect of sediment cores collected from a blue hole near Middle Caicos in the Turks & Caicos Islands. Storm deposits found across cores in the transect record the passage of hurricanes passing to the south of Middle Caicos over the past 1500 years including Hurricane Irma in 2017. The record indicates historically unprecedented multi-decadal periods of elevated storm strikes on the island. We add this new reconstruction to a compilation of near-annually resolved paleohurricane records of the past millennium in The Bahamas. This compilation indicates increased storm activity in The Bahamas from 650 to 800 CE, 930 to 1040 CE, and 1400 to 1800 CE. Taken together with compilations of published paleohurricane records from New England and the Gulf Coast of Florida, we observe periods of elevated hurricane activity in all three spatially disparate regions over the past millennium and periods when New England and the Bahama Archipelago are active while the Gulf Coast of Florida is not. We argue that both regional-scale changes in vertical wind shear patterns and shifting storm tracks may explain the discrepancies we observe between different regions of the North Atlantic. This research informs how hurricane frequency has changed over the past 1500 years specifically in the Turks & Caicos Islands and regionally along the Bahama Archipelago.